Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Japan; Japan Science and Technology Agency (JST-CREST), Chiyoda-ku, Tokyo 102-0075, Japan.
Bioresour Technol. 2012 Apr;110:474-9. doi: 10.1016/j.biortech.2012.01.091. Epub 2012 Jan 28.
Optimization of the light conditions for biofuel production by the microalga Botryococcus braunii BOT-22 (race B) was performed using monochromatic red light. The lipid and sugar contents were approximately 40% and 20-30% of the cell dry weight, respectively, and about half of the lipids were liquid hydrocarbons. The half-saturation intensities for the production rate of lipids, hydrocarbons, and sugars were 63, 49, and 44μmolm(-2)s(-1), respectively. Fluorescence microscopic images of Nile Red-stained cells showed an increased number of intracellular neutral lipid granules due to increased light intensity. After 16days of incubation in the dark, lipid and sugar, but not hydrocarbon content decreased. Growth, metabolite production, and photosynthesis were saturated at 100, 200 and 1000μmolm(-2)s(-1), respectively. These results indicate that photosynthetically captured energy is not used efficiently for metabolite production; thus, improvements in metabolic regulation may increase hydrocarbon production.
采用单色红光对微藻 Botryococcus braunii BOT-22（B 型）生物燃料生产的光照条件进行了优化。脂质和糖的含量分别约为细胞干重的 40%和 20-30%，大约一半的脂质是液态烃类。脂质、烃类和糖的生产速率的半饱和强度分别为 63、49 和 44μmolm(-2)s(-1)。尼罗红染色细胞的荧光显微镜图像显示，由于光强度增加，细胞内中性脂滴的数量增加。在黑暗中培养 16 天后，脂质和糖的含量（但不包括烃类）下降。生长、代谢产物的产生和光合作用分别在 100、200 和 1000μmolm(-2)s(-1)时达到饱和。这些结果表明，光合作用捕获的能量没有被有效地用于代谢产物的生产；因此，代谢调控的改进可能会增加烃类的产量。
